systemd/extras/path_id

#!/bin/sh
#set -x

# this script should provide the shortest possible unique hardware path 
# to a block device
#

# Horrible script. Handle with extreme care.

# to be called from udev
# DEVPATH=/block/sda/sda3 $0  (or similar)
# $0 /block/sda
# $0 /sys/block/sda

# example for all:
# for i in `find /sys/block -name dev` ;do DEVPATH="`echo $i | sed -e 's@^/sys\|/dev@@g'`" $0 ; done

# examples:
# SCSI cdrom
# /block/sr0 -> /devices/pci0002:30/0002:30:0c.0/host0/0:0:1:0
# result: pci-0002:30:0c.0-scsi-0:0:1:0
# SCSI disk
# /block/sda -> /devices/pci0002:30/0002:30:0c.0/host0/0:0:4:0
# result: pci-0002:30:0c.0-scsi-0:0:4:0 
# SATA disk, 4 channels per controller
# /block/sda -> /devices/pci0001:00/0001:00:07.0/0001:05:0c.0/host0/0:0:0:0
# result: pci-0001:05:0c.0-scsi-0:0:0:0
# IDE disk
# /block/hda -> /devices/pci0002:02/0002:02:0d.0/ide0/0.0
# result: pci-0002:02:0d.0-ide-0.0
# IDE cdrom on a Mac ASIC:
# /block/hdc -> /devices/pci0001:01/0001:01:17.0/0.80000000:mac-io/0.00020000:ata-3/ide1/1.0
# result: mac-io_ata-3_master
# IDE cdrom on a Mac ASIC, with ide-scsi:
# /block/sr0 -> /devices/pci0001:01/0001:01:17.0/0.80000000:mac-io/0.0001f000:ata-4/ide0/0.1/host2/2:0:0:0
# result: mac-io_ata-4_slave

# USB CDrom drive without 'serial' number:
# reusing 'product' and 'manufacturer' string, if available
# /block/sr0 -> /devices/pci0001:00/0001:00:04.0/0001:02:0b.0/usb4/4-2/4-2:1.0/host4/4:0:0:0
# result: usb-storage-odd-Freecom-USIDERev930:0:0:0

# devices may have several interfaces on one PCI device, like IDE:
# pci-0001:00:04.0_ide1-master
# pci-0001:00:04.0_ide2-master
# pci-0001:00:04.0_ide2-slave
# they are marked as ports, it is expected that the driver shows
# ide1 even if there is nothing connected to either master or slave
# interface
#
# match order is important.
# first IDE to find ide-scsi devices.
# then SCSI
# first usb-storage
# then firewire sbp2
# then the rest

PATH=/lib/klibc/bin #/usr:/usr/sbin:/usr/bin:/sbin:/bin
SYSFS=/sys
export PATH
RESULT=1
CDROM=
TYPE=
OPWD="`pwd`"
# Check for 'pwd -P'
if $(pwd -P > /dev/null 2>&1); then
    pwd_cmd="pwd -P"
else
    pwd_cmd="pwd"
fi
full_sysfs_class_path=
full_sysfs_device_path=

if [ -z "$DEVPATH" -a -z "$1" ] ; then
    exit 1
fi

if [ -z "$DEVPATH" ] ; then
    case "$1" in
	$SYSFS/*)
	    DEVPATH="${1#$SYSFS}"
	    ;;
	*)
	    DEVPATH=$1
	    ;;
    esac
fi

if [ ! -d $SYSFS$DEVPATH ] ; then
    exit 1
fi
if [ ! -f $SYSFS$DEVPATH/dev ] ; then
    exit 1
fi

case "$DEVPATH" in
    /block/*)
	TYPE=block
	;;
    /class/*)
	TYPE="${DEVPATH#/class/}"
	TYPE="${TYPE%%/*}"
	;;
    *)
	exit 1
	;;
esac
	
#
##
#

get_port () {
    local type offset port
    type=$1
    offset=$2
    for i in $type[0-9]* ; do
	: i $i
	port="${i#$type}"
	if [ "$port" -lt "$offset" ] ; then offset=$port ; fi
    done
    if [ "$port" != "0" ] ; then
	echo $(($2 - $offset))
    fi
}

handle_block_ide () {
: handle_block_ide $*
	local DEV=$1
	local port idedev idecontroller
	# IDE
	: DEV $DEV
	d=$DEV
	case "$DEV" in
	# remove ide-scsi part, leave only channel info
		*/ide[0-9]*/host[0-9]*)
		while [ ! -z "$d" ] ; do
			case "$d" in
				*/host[0-9]*)
				d="${d%/*}"
				continue
				;;
				*)
				break
				;;
			esac
		done
		;;
	esac
	idedev=$d
	while [ ! -z "$d" ] ; do
		case "$d" in
			*/ide[0-9]*)
			port="${d##*/}"
			d="${d%/*}"
			continue
			;;
			*)
			break
			;;
		esac
	done
	idecontroller=$d
	# port info if the controller has more than one interface
	port="${port#ide}"
	: port $port d $d
	: idedev $idedev kernel_port $port
	case "${idedev##*.}" in
		 0)
		 channel=0
		 ;;
		 1)
		 channel=1
		 ;;
		 *)
		 echo "Error: $idedev is neither master or slave" >&2
	esac
	case "$d" in
		*:mac-io/*)
		: mac-io: $d
		d="`echo $d | sed -e 's@^.*:mac-io[^:]\+:\([^/]\+\).*@mac-io_\1@'`"
		;;
		/sys/devices)
		# PCMCIA devices
		ifname=${full_sysfs_class_path##*/}
		set -- `sed -n "/$ifname/p" /var/lib/pcmcia/stab`
		d="pcmcia-$1"
		;;
		*)
		d="pci-${d##*/}"
		# d="`echo $d | sed -e 's@^.*/\([^/]\{1,\}\)/.@pci-\1@'`"
		;;
	esac

	cd $idecontroller
	port="`get_port ide $port`"
	cd "$OPWD"
	:  hardware_port $port
	if [ -z "$port" ] ; then
		d="${d}-ide-0:$channel"
	else
		d="${d}-ide-${port}:$channel"
	fi
	   
	RESULT=0
}

handle_block_scsi () {
: handle_block_scsi $*
	local DEV=$1
	local cil controller_port controller_dev
	# SCSI device
	cil="${DEV##*/}"
	cil="${cil#*:}"
	controller_dev=$DEV
	while [ ! -z "$controller_dev" ] ; do
		case "$controller_dev" in
			*/host[0-9]*)
			controller_port=$controller_dev
			controller_dev="${controller_dev%/*}"
			;;
			*) break ;;
		esac
	done
	: controller_dev $controller_dev
	: controller_port $controller_port
	# a host controller may have more than one interface/port
	controller_port="${controller_port##*/}"
	controller_port="${controller_port##host}"
	#
	case "$controller_dev" in
		# grand central, old powermacs
		*:gc/*)
		adapter="`echo $controller_dev |  sed -e 's@/[^/]\{1,\}$@@;s@^.*/@@;s@^.*:@@'`"
		bus="gc"
		;;
		*)
		adapter="${controller_dev##*/}"
		bus="pci"
		;;
	esac
	cd "$controller_dev"
	controller_port="`get_port host $controller_port`"
	cd "$OPWD"
	d="$bus-$adapter"
	if [ -z "$controller_port" ] ; then
		controller_port=0
	fi
	d="${d}-scsi-${controller_port}:${cil}"
	RESULT=0
}

handle_block_usb_storage () {
: handle_block_usb_storage $*
	local DEV=$1
	cil="${DEV##*/}"
	cil="${cil#*:}"
	controller_dev=$DEV
	while [ ! -z "$controller_dev" ] ; do
		case "$controller_dev" in
			*/host[0-9]*)
			controller_dev="${controller_dev%/*}"
			;;
			*) break ;;
		esac
	done
	: controller_dev $controller_dev
	#
	# usb-storage devs have a serial number, hopefully unique
	serial=
	if [ -f $controller_dev/../serial ] ; then
		serial="`sed -e 's@^[ -]\{1,\}\|[ -]\{1,\}$@@g;s@[^abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-_0123456789]@@g' < $controller_dev/../serial`"
		: serial XXX_${serial}_XXX
		d="usb-$serial"
		serial="`echo $serial | sed -e 's@[ 0]\{1,\}@@g'`"
	fi
	if [ -z "$serial" ] ; then
		# no serial, broken device
		# has eventually binary junk in vpd
		identifier=
		if [ -f $controller_dev/../product ] ; then
		product="`sed -e 's@^[ -]\{1,\}\|[ -]\{1,\}$@@g;s@[^abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-_0123456789]@@g' < $controller_dev/../product`"
		fi
		if [ -f $controller_dev/../manufacturer ] ; then
		manufacturer="`sed -e 's@^[ -]\{1,\}\|[ -]\{1,\}$@@g;s@[^abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-_0123456789]@@g' < $controller_dev/../manufacturer`"
		fi
		if [ -z "$product" -o -z "$manufacturer" ] ; then
			read idvendor < $controller_dev/../idVendor
			read idproduct < $controller_dev/../idProduct
			identifier="0x${idvendor}-0x${idproduct}"
		else
			identifier="${manufacturer}-${product}"
		fi
		d="usb-${identifier}"
	fi
	d="$d:$cil"
	RESULT=0


}

handle_block () {
    full_sysfs_class_path="$SYSFS$DEVPATH"
    if [ ! -f $full_sysfs_class_path/dev ] ; then return ; fi
    # the main device has (hopefully) a symlink to the real device
    # a partition is a subdir of the main (raw) device
    if [ ! -L $full_sysfs_class_path/device ] ; then
	if [ -f $full_sysfs_class_path/range ] ; then return ; fi
	full_sysfs_class_path="${full_sysfs_class_path%/*}"
	: full_sysfs_class_path "$full_sysfs_class_path"
	if [ ! -L $full_sysfs_class_path/device -o ! -f $full_sysfs_class_path/dev ] ; then
	    return
	fi
    fi
    cd $full_sysfs_class_path/device
    full_sysfs_device_path="`$pwd_cmd`"
    cd "$OPWD"
    D=$full_sysfs_device_path
    case "$D" in
	*/ide[0-9]/[0-9].[0-9]*|*/ide[0-9][0-9]/[0-9][0-9].[0-9]*)
	handle_block_ide "$D"
	;;
	*/usb[0-9]*/[0-9]*/host[0-9]*/[0-9]*:[0-9]*:[0-9]*:[0-9]*)
	handle_block_usb_storage "$D"
	;;
	*/css0/*)
	if [ -r $full_sysfs_device_path/wwpn ]; then
	    read wwpn < $full_sysfs_device_path/wwpn
	fi
	if [ -r $full_sysfs_device_path/fcp_lun ]; then
	    read lun < $full_sysfs_device_path/fcp_lun
	fi
	if [ -r $full_sysfs_device_path/hba_id ]; then
	    read bus_id < $full_sysfs_device_path/hba_id
	fi
	if [ "$bus_id" -a "$wwpn" -a "$lun" ]; then
	    # S/390 zfcp adapter
	    d="ccw-$bus_id-zfcp-$wwpn:$lun"
	    RESULT=0
	else
	    # DASD devices
	    bus="ccw"
	    adapter=${D##*/}
	    d="$bus-$adapter"
	    RESULT=0
	fi
	;;
	*/host[0-9]*/[0-9]*:[0-9]*:[0-9]*:[0-9]*)
	# check for ieee1394 sbp2 
	if test -f $D/ieee1394_id ; then
	    read ieee1394_id < $D/ieee1394_id
	    d="`echo ieee1394-${ieee1394_id} | sed -e 's@:@-@g'`"
	    RESULT=0
	else
	    handle_block_scsi "$D"
	fi
	;;

	*)
	: not handled
	RESULT=1
	return

	;;
    esac
    # look for a partition
    if [ "$full_sysfs_class_path" != "$SYSFS$DEVPATH" ] ; then
	dp="`echo $SYSFS$DEVPATH | sed -e 's@^/.*/@@;s@^[^0-9]\{1,\}@@;s@.*_@@'`"
	case "$d" in
	    *[0-9])
	    d="${d}p${dp}"
	    ;;
	    *)
		d="${d}${dp}"
		;;
	esac
    fi
    # done
    echo "ID_PATH=$d"
}

case "$TYPE" in
	block)
	handle_block
	;;
	*)
	RESULT=1
	;;
esac
exit $RESULT